diff --git a/components/hal/include/hal/systimer_types.h b/components/hal/include/hal/systimer_types.h
index 2af2f60f30..d4583dc7ae 100644
--- a/components/hal/include/hal/systimer_types.h
+++ b/components/hal/include/hal/systimer_types.h
@@ -30,6 +30,9 @@ typedef struct {
         struct {
             uint64_t lo : SOC_SYSTIMER_BIT_WIDTH_LO; /*!< Low part of counter value */
             uint64_t hi : SOC_SYSTIMER_BIT_WIDTH_HI; /*!< High part of counter value */
+#if (SOC_SYSTIMER_BIT_WIDTH_LO  + SOC_SYSTIMER_BIT_WIDTH_HI) < 64
+            uint64_t reserved: (64 - (SOC_SYSTIMER_BIT_WIDTH_LO  + SOC_SYSTIMER_BIT_WIDTH_HI));
+#endif
         };
         uint64_t val; /*!< counter value */
     };